The U.S. Justice Department is organizing meetings with large publishing companies to seek information about how Alphabet Inc.’s Google operates in the digital advertising market, according to people familiar with the matter

In a sign the government is advancing its antitrust investigation, the agency has contacted News Corp., Conde Nast and The New York Times Co. within the last two months. At least one of the meetings, with Conde Nast representatives, already occurred, two people said.

The meetings come about five months into the Justice Department’s broad investigation into whether technology platforms, including Google, are using their dominance to...